code: def login(self, username=None, password=None):
      data = {"username": username, "password": password}
      self.auth_token = None
      resp = self.make_request(
          self.docker_hub_base_endpoint + "users/login/", "POST", data
      )
      if resp["code"] == 200:
          self.auth_token = resp["content"]["token"]
      return resp
  
file_path: mindsdb/mindsdb/integrations/handlers/dockerhub_handler/dockerhub.py
imports: import json
  import requests
label_desc: Use image node_id 3 for calling the DockerHubClient obj's underlying member method code with example usage: obj.login(username, password) and returns: resp